New forms of signal processing for hearing aids will be developed. The techniques will focus on improved methods of amplitude compression, noise reduction and two-channel signal processing for binaural hearing aids. Speech production and reception in deaf children will be investigated and improved methods of speech training using modern technological aids will be developed. Speech problems at both the segmental and suprasegmental level will be addressed. Measurements of articulatory behavior, fundamental frequency contours and breathing patterns during speech will be obtained. Tactile supplements to speechreading will be investigated. Wearable tactile displays of voice fundamental frequency and of formant frequencies will be developed and relevant data on tactile perception and speech perception and production in deaf adults will be obtained. Rehabilitation strategies for cochlear implant patients will be evaluated. Evaluation techniques for both children and adults will be developed. Methods of noise reduction for sensory aids in general will be studied. Both single-microphone and two-microphone techniques will be examined and improved methods of noise reduction and speech feature extraction in noise will be developed.